Pump not coming to pressure in cold weather

[MDrost1]

Folks,

Have a little issue. I've had this happen before on another bay.

In cold weather when the weep mizer is active, the bay(only one bay affected) has problem coming up to pressure. As if water has drained out of the pump. Once it is up to pressure is operates normally, that is until it is unused for a while, then the problem comes back.

This is a newly refurbished head with new seals and valves. I plumbed it 2 months ago. with some new fittings, some used with thread tape and a little pipe dope on the older fittings for good measure.

I replace the HP check valve, didn't help. I replaced the weep check. The problem persists. I replace the low pressure stainless check valves and manifolds in the trough this past fall. All new fittings up there. No visible leaks anywhere.

Any thoughts??

As always,

THANKS!

 

[MDrost1]

Still having this issue. Any thoughts?

 

[JMMUSTANG]

Have you notice your drip system in the other bays increasing in pressure?
Maybe some of your pressure is bleeding off into other bays.

 

[Overachiever]

I'm having the same issue with one of my spot free pumps... I thought it might be the foot valve letting the water go back into the storage tank thus causing it to starve for water for a while when it hasn't been used, but I replaced the foot valve and that didn't fix it. I'll let you know if I figure anything out as I dive into it this weekend.

 

[MDrost1]

Well,

I spent some time today. I swapped out the "cold water rinse solenoid" a normally closed Dema. I swapped the HP check for a check valve with a pretty low cracking pressure. No go. On a whim, I swapped the regulator tonight. I am hoping that is it. If it isn't, I'll be replumbing the stand with a spare pump on Monday. Thanks again for your help.

 

[cantbreak80]

Check the soap and wax solenoid fittings.

I’ve had push-to-connect fittings lose their seal, allowing air to fill the soap/wax supply line to the pump – like taking your finger off the end of the straw.

During idle time, the fluid drains from the supply line resulting in a column of air to the pump’s inlet. Once the soap or wax line refills, the pump runs smoothly.

 

[MEP001]

If you can post a video with the pump starting and struggling to reach pressure, I can probably tell you what to look for by hearing it.

 

[MDrost1]

Will do! I just swapped the head and replumbed the stand. We will see tomorrow.

 

[MDrost1]

Folks,

Back to square one. We had a little heat wave so the issue has been masked. The weep came on overnight and the issues seem to be continuing. Here are the things I have done:

1) Replaced Head to pump. All new.
2) Replumbed pump stand and reseated and reused old fittings. New regulator and check valves. My weep check looks like this:https://www.kleen-ritecorp.com/p-57402-value-line-stainless-steel-check-valve-14-f.aspx. I used the smaller: https://www.kleen-ritecorp.com/p-23214-14-fxf-teflon-check-valve-by-fluid-controls.aspx. These are on all of my other stands, and a few were on this stand before my troubleshooting expanded.
3) New gun, hose, swivel(this morning)
4) Replace LP/SFR manifolds/check valves in trough this summer.

My weep line is plumbed on the 3/8" discharge(top hole, inline with pressure gauge). It is on the opposite side from the HP hose. Randy suggested moving it to the other side. I have not done this yet, as all of my stands are plumbed this way and work fine. This is on my list though. Thanks Randy.

This thing runs smooth as the day is long, when it is warm! I can't figure it out. I am letting it cool down and will post a video soon! Thanks!

 

[MDrost1]

So here's the video. I started the bay this morning about 9am. Left it until 11am. 29 degrees on the weep mizer. This is when I shot the video. Not so bad. I comes to 800psi, then stutters, then to 1000psi. Before all of the work it was much worse. Please let me know what you think.

https://youtu.be/-KDpgByl3KQ

 

[MEP001]

It sounds like it might be starving for water and cavitating. Do you get a burst of air at the bay when you first turn it on? I've sometimes had to restrict the water to the pump to get it to draw soap and wax, and if the water drains from the line to the bay the pump can cavitate as it tries to pull more than it can through the restricted valve until the line is purged.

Does it draw hot water from a tank and have a solenoid for city-pressure feed on rinse, and if so does it always pressure up on rinse?

 

[MDrost1]

MEP001,
It does draw on a tank and solenoid. It usually always comes up to pressure.

So as a last ditch effort, I swapped the whole gun/hose/tip assembly with a brand new one. I also swapped the pulse dampener(who knows, right). She's running like a champ.

Can older weep guns cause this??

 

[MEP001]

Maybe you had a leaking swivel letting the liquid drain out of the hose. I don't see how the gun could cause it.

 

[Robert2181]

I have always found it to be lack of water or restriction.

 

[MDrost1]

Interesting. So to much water could cause this....hmmm.

 

[Randy]

Never heard that one before. But I guess it could be. Now try taking the bad gun, nozzle and hose and put it on another bay and see if it acts up.

 

[MDrost1]

So this is still happening. I tried everyone’s suggestions at this point. It only happens when the cycled weep is active. Full weep, all good. No weep, all good.

My cold water hp rinse solenoids are very old, and could be bad. Not sure though. Would this cause this?

 

[Overachiever]

I know I said I'd update when I figured out why my pump was doing that and it ended up being a loose hose clamp on the tubing that pulled the water from the spot free tank. I don't see how the solenoid could be to blame but maybe someone smarter than me could chime in.

 

[MDrost1]

It’s weird. This only happens on two, sometimes three bays. The closest to the equipment room. The far bays seem fine.

Yesterday I changed the weep location to be on the hp hose side of the pump on 3 of the bays that are affected now. Didn’t cure the issue.

 

[MEP001]

I still feel like it's cavitation. Do you have the rinse supply from city pressure or does everything draw from the same tank?